// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2015 Benoit Jacob <benoitjacob@google.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include <algorithm>
#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <iostream>
#include <memory>
#include <string>
#include <vector>

#include <Eigen/Core>

using namespace std;

const int default_precision = 4;

// see --only-cubic-sizes
bool only_cubic_sizes = false;

// see --dump-tables
bool dump_tables = false;

uint8_t
log2_pot(size_t x)
{
	size_t l = 0;
	while (x >>= 1)
		l++;
	return l;
}

uint16_t
compact_size_triple(size_t k, size_t m, size_t n)
{
	return (log2_pot(k) << 8) | (log2_pot(m) << 4) | log2_pot(n);
}

// just a helper to store a triple of K,M,N sizes for matrix product
struct size_triple_t
{
	uint16_t k, m, n;
	size_triple_t()
		: k(0)
		, m(0)
		, n(0)
	{
	}
	size_triple_t(size_t _k, size_t _m, size_t _n)
		: k(_k)
		, m(_m)
		, n(_n)
	{
	}
	size_triple_t(const size_triple_t& o)
		: k(o.k)
		, m(o.m)
		, n(o.n)
	{
	}
	size_triple_t(uint16_t compact)
	{
		k = 1 << ((compact & 0xf00) >> 8);
		m = 1 << ((compact & 0x0f0) >> 4);
		n = 1 << ((compact & 0x00f) >> 0);
	}
	bool is_cubic() const { return k == m && m == n; }
};

ostream&
operator<<(ostream& s, const size_triple_t& t)
{
	return s << "(" << t.k << ", " << t.m << ", " << t.n << ")";
}

struct inputfile_entry_t
{
	uint16_t product_size;
	uint16_t pot_block_size;
	size_triple_t nonpot_block_size;
	float gflops;
};

struct inputfile_t
{
	enum class type_t
	{
		unknown,
		all_pot_sizes,
		default_sizes
	};

	string filename;
	vector<inputfile_entry_t> entries;
	type_t type;

	inputfile_t(const string& fname)
		: filename(fname)
		, type(type_t::unknown)
	{
		ifstream stream(filename);
		if (!stream.is_open()) {
			cerr << "couldn't open input file: " << filename << endl;
			exit(1);
		}
		string line;
		while (getline(stream, line)) {
			if (line.empty())
				continue;
			if (line.find("BEGIN MEASUREMENTS ALL POT SIZES") == 0) {
				if (type != type_t::unknown) {
					cerr << "Input file " << filename << " contains redundant BEGIN MEASUREMENTS lines";
					exit(1);
				}
				type = type_t::all_pot_sizes;
				continue;
			}
			if (line.find("BEGIN MEASUREMENTS DEFAULT SIZES") == 0) {
				if (type != type_t::unknown) {
					cerr << "Input file " << filename << " contains redundant BEGIN MEASUREMENTS lines";
					exit(1);
				}
				type = type_t::default_sizes;
				continue;
			}

			if (type == type_t::unknown) {
				continue;
			}
			switch (type) {
				case type_t::all_pot_sizes: {
					unsigned int product_size, block_size;
					float gflops;
					int sscanf_result = sscanf(line.c_str(), "%x %x %f", &product_size, &block_size, &gflops);
					if (3 != sscanf_result || !product_size || product_size > 0xfff || !block_size ||
						block_size > 0xfff || !isfinite(gflops)) {
						cerr << "ill-formed input file: " << filename << endl;
						cerr << "offending line:" << endl << line << endl;
						exit(1);
					}
					if (only_cubic_sizes && !size_triple_t(product_size).is_cubic()) {
						continue;
					}
					inputfile_entry_t entry;
					entry.product_size = uint16_t(product_size);
					entry.pot_block_size = uint16_t(block_size);
					entry.gflops = gflops;
					entries.push_back(entry);
					break;
				}
				case type_t::default_sizes: {
					unsigned int product_size;
					float gflops;
					int bk, bm, bn;
					int sscanf_result =
						sscanf(line.c_str(), "%x default(%d, %d, %d) %f", &product_size, &bk, &bm, &bn, &gflops);
					if (5 != sscanf_result || !product_size || product_size > 0xfff || !isfinite(gflops)) {
						cerr << "ill-formed input file: " << filename << endl;
						cerr << "offending line:" << endl << line << endl;
						exit(1);
					}
					if (only_cubic_sizes && !size_triple_t(product_size).is_cubic()) {
						continue;
					}
					inputfile_entry_t entry;
					entry.product_size = uint16_t(product_size);
					entry.pot_block_size = 0;
					entry.nonpot_block_size = size_triple_t(bk, bm, bn);
					entry.gflops = gflops;
					entries.push_back(entry);
					break;
				}

				default:
					break;
			}
		}
		stream.close();
		if (type == type_t::unknown) {
			cerr << "Unrecognized input file " << filename << endl;
			exit(1);
		}
		if (entries.empty()) {
			cerr << "didn't find any measurements in input file: " << filename << endl;
			exit(1);
		}
	}
};

struct preprocessed_inputfile_entry_t
{
	uint16_t product_size;
	uint16_t block_size;

	float efficiency;
};

bool
lower_efficiency(const preprocessed_inputfile_entry_t& e1, const preprocessed_inputfile_entry_t& e2)
{
	return e1.efficiency < e2.efficiency;
}

struct preprocessed_inputfile_t
{
	string filename;
	vector<preprocessed_inputfile_entry_t> entries;

	preprocessed_inputfile_t(const inputfile_t& inputfile)
		: filename(inputfile.filename)
	{
		if (inputfile.type != inputfile_t::type_t::all_pot_sizes) {
			abort();
		}
		auto it = inputfile.entries.begin();
		auto it_first_with_given_product_size = it;
		while (it != inputfile.entries.end()) {
			++it;
			if (it == inputfile.entries.end() || it->product_size != it_first_with_given_product_size->product_size) {
				import_input_file_range_one_product_size(it_first_with_given_product_size, it);
				it_first_with_given_product_size = it;
			}
		}
	}

  private:
	void import_input_file_range_one_product_size(const vector<inputfile_entry_t>::const_iterator& begin,
												  const vector<inputfile_entry_t>::const_iterator& end)
	{
		uint16_t product_size = begin->product_size;
		float max_gflops = 0.0f;
		for (auto it = begin; it != end; ++it) {
			if (it->product_size != product_size) {
				cerr << "Unexpected ordering of entries in " << filename << endl;
				cerr << "(Expected all entries for product size " << hex << product_size << dec << " to be grouped)"
					 << endl;
				exit(1);
			}
			max_gflops = max(max_gflops, it->gflops);
		}
		for (auto it = begin; it != end; ++it) {
			preprocessed_inputfile_entry_t entry;
			entry.product_size = it->product_size;
			entry.block_size = it->pot_block_size;
			entry.efficiency = it->gflops / max_gflops;
			entries.push_back(entry);
		}
	}
};

void
check_all_files_in_same_exact_order(const vector<preprocessed_inputfile_t>& preprocessed_inputfiles)
{
	if (preprocessed_inputfiles.empty()) {
		return;
	}

	const preprocessed_inputfile_t& first_file = preprocessed_inputfiles[0];
	const size_t num_entries = first_file.entries.size();

	for (size_t i = 0; i < preprocessed_inputfiles.size(); i++) {
		if (preprocessed_inputfiles[i].entries.size() != num_entries) {
			cerr << "these files have different number of entries: " << preprocessed_inputfiles[i].filename << " and "
				 << first_file.filename << endl;
			exit(1);
		}
	}

	for (size_t entry_index = 0; entry_index < num_entries; entry_index++) {
		const uint16_t entry_product_size = first_file.entries[entry_index].product_size;
		const uint16_t entry_block_size = first_file.entries[entry_index].block_size;
		for (size_t file_index = 0; file_index < preprocessed_inputfiles.size(); file_index++) {
			const preprocessed_inputfile_t& cur_file = preprocessed_inputfiles[file_index];
			if (cur_file.entries[entry_index].product_size != entry_product_size ||
				cur_file.entries[entry_index].block_size != entry_block_size) {
				cerr << "entries not in same order between these files: " << first_file.filename << " and "
					 << cur_file.filename << endl;
				exit(1);
			}
		}
	}
}

float
efficiency_of_subset(const vector<preprocessed_inputfile_t>& preprocessed_inputfiles, const vector<size_t>& subset)
{
	if (subset.size() <= 1) {
		return 1.0f;
	}
	const preprocessed_inputfile_t& first_file = preprocessed_inputfiles[subset[0]];
	const size_t num_entries = first_file.entries.size();
	float efficiency = 1.0f;
	size_t entry_index = 0;
	size_t first_entry_index_with_this_product_size = 0;
	uint16_t product_size = first_file.entries[0].product_size;
	while (entry_index < num_entries) {
		++entry_index;
		if (entry_index == num_entries || first_file.entries[entry_index].product_size != product_size) {
			float efficiency_this_product_size = 0.0f;
			for (size_t e = first_entry_index_with_this_product_size; e < entry_index; e++) {
				float efficiency_this_entry = 1.0f;
				for (auto i = subset.begin(); i != subset.end(); ++i) {
					efficiency_this_entry =
						min(efficiency_this_entry, preprocessed_inputfiles[*i].entries[e].efficiency);
				}
				efficiency_this_product_size = max(efficiency_this_product_size, efficiency_this_entry);
			}
			efficiency = min(efficiency, efficiency_this_product_size);
			if (entry_index < num_entries) {
				first_entry_index_with_this_product_size = entry_index;
				product_size = first_file.entries[entry_index].product_size;
			}
		}
	}

	return efficiency;
}

void
dump_table_for_subset(const vector<preprocessed_inputfile_t>& preprocessed_inputfiles, const vector<size_t>& subset)
{
	const preprocessed_inputfile_t& first_file = preprocessed_inputfiles[subset[0]];
	const size_t num_entries = first_file.entries.size();
	size_t entry_index = 0;
	size_t first_entry_index_with_this_product_size = 0;
	uint16_t product_size = first_file.entries[0].product_size;
	size_t i = 0;
	size_triple_t min_product_size(first_file.entries.front().product_size);
	size_triple_t max_product_size(first_file.entries.back().product_size);
	if (!min_product_size.is_cubic() || !max_product_size.is_cubic()) {
		abort();
	}
	if (only_cubic_sizes) {
		cerr << "Can't generate tables with --only-cubic-sizes." << endl;
		abort();
	}
	cout << "struct LookupTable {" << endl;
	cout << "  static const size_t BaseSize = " << min_product_size.k << ";" << endl;
	const size_t NumSizes = log2_pot(max_product_size.k / min_product_size.k) + 1;
	const size_t TableSize = NumSizes * NumSizes * NumSizes;
	cout << "  static const size_t NumSizes = " << NumSizes << ";" << endl;
	cout << "  static const unsigned short* Data() {" << endl;
	cout << "    static const unsigned short data[" << TableSize << "] = {";
	while (entry_index < num_entries) {
		++entry_index;
		if (entry_index == num_entries || first_file.entries[entry_index].product_size != product_size) {
			float best_efficiency_this_product_size = 0.0f;
			uint16_t best_block_size_this_product_size = 0;
			for (size_t e = first_entry_index_with_this_product_size; e < entry_index; e++) {
				float efficiency_this_entry = 1.0f;
				for (auto i = subset.begin(); i != subset.end(); ++i) {
					efficiency_this_entry =
						min(efficiency_this_entry, preprocessed_inputfiles[*i].entries[e].efficiency);
				}
				if (efficiency_this_entry > best_efficiency_this_product_size) {
					best_efficiency_this_product_size = efficiency_this_entry;
					best_block_size_this_product_size = first_file.entries[e].block_size;
				}
			}
			if ((i++) % NumSizes) {
				cout << " ";
			} else {
				cout << endl << "      ";
			}
			cout << "0x" << hex << best_block_size_this_product_size << dec;
			if (entry_index < num_entries) {
				cout << ",";
				first_entry_index_with_this_product_size = entry_index;
				product_size = first_file.entries[entry_index].product_size;
			}
		}
	}
	if (i != TableSize) {
		cerr << endl << "Wrote " << i << " table entries, expected " << TableSize << endl;
		abort();
	}
	cout << endl << "    };" << endl;
	cout << "    return data;" << endl;
	cout << "  }" << endl;
	cout << "};" << endl;
}

float
efficiency_of_partition(const vector<preprocessed_inputfile_t>& preprocessed_inputfiles,
						const vector<vector<size_t>>& partition)
{
	float efficiency = 1.0f;
	for (auto s = partition.begin(); s != partition.end(); ++s) {
		efficiency = min(efficiency, efficiency_of_subset(preprocessed_inputfiles, *s));
	}
	return efficiency;
}

void
make_first_subset(size_t subset_size, vector<size_t>& out_subset, size_t set_size)
{
	assert(subset_size >= 1 && subset_size <= set_size);
	out_subset.resize(subset_size);
	for (size_t i = 0; i < subset_size; i++) {
		out_subset[i] = i;
	}
}

bool
is_last_subset(const vector<size_t>& subset, size_t set_size)
{
	return subset[0] == set_size - subset.size();
}

void
next_subset(vector<size_t>& inout_subset, size_t set_size)
{
	if (is_last_subset(inout_subset, set_size)) {
		cerr << "iterating past the last subset" << endl;
		abort();
	}
	size_t i = 1;
	while (inout_subset[inout_subset.size() - i] == set_size - i) {
		i++;
		assert(i <= inout_subset.size());
	}
	size_t first_index_to_change = inout_subset.size() - i;
	inout_subset[first_index_to_change]++;
	size_t p = inout_subset[first_index_to_change];
	for (size_t j = first_index_to_change + 1; j < inout_subset.size(); j++) {
		inout_subset[j] = ++p;
	}
}

const size_t number_of_subsets_limit = 100;
const size_t always_search_subsets_of_size_at_least = 2;

bool
is_number_of_subsets_feasible(size_t n, size_t p)
{
	assert(n > 0 && p > 0 && p <= n);
	uint64_t numerator = 1, denominator = 1;
	for (size_t i = 0; i < p; i++) {
		numerator *= n - i;
		denominator *= i + 1;
		if (numerator > denominator * number_of_subsets_limit) {
			return false;
		}
	}
	return true;
}

size_t
max_feasible_subset_size(size_t n)
{
	assert(n > 0);
	const size_t minresult = min<size_t>(n - 1, always_search_subsets_of_size_at_least);
	for (size_t p = 1; p <= n - 1; p++) {
		if (!is_number_of_subsets_feasible(n, p + 1)) {
			return max(p, minresult);
		}
	}
	return n - 1;
}

void
find_subset_with_efficiency_higher_than(const vector<preprocessed_inputfile_t>& preprocessed_inputfiles,
										float required_efficiency_to_beat,
										vector<size_t>& inout_remainder,
										vector<size_t>& out_subset)
{
	out_subset.resize(0);

	if (required_efficiency_to_beat >= 1.0f) {
		cerr << "can't beat efficiency 1." << endl;
		abort();
	}

	while (!inout_remainder.empty()) {

		vector<size_t> candidate_indices(inout_remainder.size());
		for (size_t i = 0; i < candidate_indices.size(); i++) {
			candidate_indices[i] = i;
		}

		size_t candidate_indices_subset_size = max_feasible_subset_size(candidate_indices.size());
		while (candidate_indices_subset_size >= 1) {
			vector<size_t> candidate_indices_subset;
			make_first_subset(candidate_indices_subset_size, candidate_indices_subset, candidate_indices.size());

			vector<size_t> best_candidate_indices_subset;
			float best_efficiency = 0.0f;
			vector<size_t> trial_subset = out_subset;
			trial_subset.resize(out_subset.size() + candidate_indices_subset_size);
			while (true) {
				for (size_t i = 0; i < candidate_indices_subset_size; i++) {
					trial_subset[out_subset.size() + i] = inout_remainder[candidate_indices_subset[i]];
				}

				float trial_efficiency = efficiency_of_subset(preprocessed_inputfiles, trial_subset);
				if (trial_efficiency > best_efficiency) {
					best_efficiency = trial_efficiency;
					best_candidate_indices_subset = candidate_indices_subset;
				}
				if (is_last_subset(candidate_indices_subset, candidate_indices.size())) {
					break;
				}
				next_subset(candidate_indices_subset, candidate_indices.size());
			}

			if (best_efficiency > required_efficiency_to_beat) {
				for (size_t i = 0; i < best_candidate_indices_subset.size(); i++) {
					candidate_indices[i] = candidate_indices[best_candidate_indices_subset[i]];
				}
				candidate_indices.resize(best_candidate_indices_subset.size());
			}
			candidate_indices_subset_size--;
		}

		size_t candidate_index = candidate_indices[0];
		auto candidate_iterator = inout_remainder.begin() + candidate_index;
		vector<size_t> trial_subset = out_subset;

		trial_subset.push_back(*candidate_iterator);
		float trial_efficiency = efficiency_of_subset(preprocessed_inputfiles, trial_subset);
		if (trial_efficiency > required_efficiency_to_beat) {
			out_subset.push_back(*candidate_iterator);
			inout_remainder.erase(candidate_iterator);
		} else {
			break;
		}
	}
}

void
find_partition_with_efficiency_higher_than(const vector<preprocessed_inputfile_t>& preprocessed_inputfiles,
										   float required_efficiency_to_beat,
										   vector<vector<size_t>>& out_partition)
{
	out_partition.resize(0);

	vector<size_t> remainder;
	for (size_t i = 0; i < preprocessed_inputfiles.size(); i++) {
		remainder.push_back(i);
	}

	while (!remainder.empty()) {
		vector<size_t> new_subset;
		find_subset_with_efficiency_higher_than(
			preprocessed_inputfiles, required_efficiency_to_beat, remainder, new_subset);
		out_partition.push_back(new_subset);
	}
}

void
print_partition(const vector<preprocessed_inputfile_t>& preprocessed_inputfiles,
				const vector<vector<size_t>>& partition)
{
	float efficiency = efficiency_of_partition(preprocessed_inputfiles, partition);
	cout << "Partition into " << partition.size() << " subsets for " << efficiency * 100.0f << "% efficiency" << endl;
	for (auto subset = partition.begin(); subset != partition.end(); ++subset) {
		cout << "  Subset " << (subset - partition.begin()) << ", efficiency "
			 << efficiency_of_subset(preprocessed_inputfiles, *subset) * 100.0f << "%:" << endl;
		for (auto file = subset->begin(); file != subset->end(); ++file) {
			cout << "    " << preprocessed_inputfiles[*file].filename << endl;
		}
		if (dump_tables) {
			cout << "  Table:" << endl;
			dump_table_for_subset(preprocessed_inputfiles, *subset);
		}
	}
	cout << endl;
}

struct action_t
{
	virtual const char* invokation_name() const
	{
		abort();
		return nullptr;
	}
	virtual void run(const vector<string>&) const { abort(); }
	virtual ~action_t() {}
};

struct partition_action_t : action_t
{
	virtual const char* invokation_name() const override { return "partition"; }
	virtual void run(const vector<string>& input_filenames) const override
	{
		vector<preprocessed_inputfile_t> preprocessed_inputfiles;

		if (input_filenames.empty()) {
			cerr << "The " << invokation_name() << " action needs a list of input files." << endl;
			exit(1);
		}

		for (auto it = input_filenames.begin(); it != input_filenames.end(); ++it) {
			inputfile_t inputfile(*it);
			switch (inputfile.type) {
				case inputfile_t::type_t::all_pot_sizes:
					preprocessed_inputfiles.emplace_back(inputfile);
					break;
				case inputfile_t::type_t::default_sizes:
					cerr << "The " << invokation_name() << " action only uses measurements for all pot sizes, and "
						 << "has no use for " << *it << " which contains measurements for default sizes." << endl;
					exit(1);
					break;
				default:
					cerr << "Unrecognized input file: " << *it << endl;
					exit(1);
			}
		}

		check_all_files_in_same_exact_order(preprocessed_inputfiles);

		float required_efficiency_to_beat = 0.0f;
		vector<vector<vector<size_t>>> partitions;
		cerr << "searching for partitions...\r" << flush;
		while (true) {
			vector<vector<size_t>> partition;
			find_partition_with_efficiency_higher_than(preprocessed_inputfiles, required_efficiency_to_beat, partition);
			float actual_efficiency = efficiency_of_partition(preprocessed_inputfiles, partition);
			cerr << "partition " << preprocessed_inputfiles.size() << " files into " << partition.size()
				 << " subsets for " << 100.0f * actual_efficiency << " % efficiency"
				 << "                  \r" << flush;
			partitions.push_back(partition);
			if (partition.size() == preprocessed_inputfiles.size() || actual_efficiency == 1.0f) {
				break;
			}
			required_efficiency_to_beat = actual_efficiency;
		}
		cerr << "                                                                  " << endl;
		while (true) {
			bool repeat = false;
			for (size_t i = 0; i < partitions.size() - 1; i++) {
				if (partitions[i].size() >= partitions[i + 1].size()) {
					partitions.erase(partitions.begin() + i);
					repeat = true;
					break;
				}
			}
			if (!repeat) {
				break;
			}
		}
		for (auto it = partitions.begin(); it != partitions.end(); ++it) {
			print_partition(preprocessed_inputfiles, *it);
		}
	}
};

struct evaluate_defaults_action_t : action_t
{
	struct results_entry_t
	{
		uint16_t product_size;
		size_triple_t default_block_size;
		uint16_t best_pot_block_size;
		float default_gflops;
		float best_pot_gflops;
		float default_efficiency;
	};
	friend ostream& operator<<(ostream& s, const results_entry_t& entry)
	{
		return s << "Product size " << size_triple_t(entry.product_size) << ": default block size "
				 << entry.default_block_size << " -> " << entry.default_gflops
				 << " GFlop/s = " << entry.default_efficiency * 100.0f << " %"
				 << " of best POT block size " << size_triple_t(entry.best_pot_block_size) << " -> "
				 << entry.best_pot_gflops << " GFlop/s" << dec;
	}
	static bool lower_efficiency(const results_entry_t& e1, const results_entry_t& e2)
	{
		return e1.default_efficiency < e2.default_efficiency;
	}
	virtual const char* invokation_name() const override { return "evaluate-defaults"; }
	void show_usage_and_exit() const
	{
		cerr << "usage: " << invokation_name() << " default-sizes-data all-pot-sizes-data" << endl;
		cerr << "checks how well the performance with default sizes compares to the best "
			 << "performance measured over all POT sizes." << endl;
		exit(1);
	}
	virtual void run(const vector<string>& input_filenames) const override
	{
		if (input_filenames.size() != 2) {
			show_usage_and_exit();
		}
		inputfile_t inputfile_default_sizes(input_filenames[0]);
		inputfile_t inputfile_all_pot_sizes(input_filenames[1]);
		if (inputfile_default_sizes.type != inputfile_t::type_t::default_sizes) {
			cerr << inputfile_default_sizes.filename << " is not an input file with default sizes." << endl;
			show_usage_and_exit();
		}
		if (inputfile_all_pot_sizes.type != inputfile_t::type_t::all_pot_sizes) {
			cerr << inputfile_all_pot_sizes.filename << " is not an input file with all POT sizes." << endl;
			show_usage_and_exit();
		}
		vector<results_entry_t> results;
		vector<results_entry_t> cubic_results;

		uint16_t product_size = 0;
		auto it_all_pot_sizes = inputfile_all_pot_sizes.entries.begin();
		for (auto it_default_sizes = inputfile_default_sizes.entries.begin();
			 it_default_sizes != inputfile_default_sizes.entries.end();
			 ++it_default_sizes) {
			if (it_default_sizes->product_size == product_size) {
				continue;
			}
			product_size = it_default_sizes->product_size;
			while (it_all_pot_sizes != inputfile_all_pot_sizes.entries.end() &&
				   it_all_pot_sizes->product_size != product_size) {
				++it_all_pot_sizes;
			}
			if (it_all_pot_sizes == inputfile_all_pot_sizes.entries.end()) {
				break;
			}
			uint16_t best_pot_block_size = 0;
			float best_pot_gflops = 0;
			for (auto it = it_all_pot_sizes;
				 it != inputfile_all_pot_sizes.entries.end() && it->product_size == product_size;
				 ++it) {
				if (it->gflops > best_pot_gflops) {
					best_pot_gflops = it->gflops;
					best_pot_block_size = it->pot_block_size;
				}
			}
			results_entry_t entry;
			entry.product_size = product_size;
			entry.default_block_size = it_default_sizes->nonpot_block_size;
			entry.best_pot_block_size = best_pot_block_size;
			entry.default_gflops = it_default_sizes->gflops;
			entry.best_pot_gflops = best_pot_gflops;
			entry.default_efficiency = entry.default_gflops / entry.best_pot_gflops;
			results.push_back(entry);

			size_triple_t t(product_size);
			if (t.k == t.m && t.m == t.n) {
				cubic_results.push_back(entry);
			}
		}

		cout << "All results:" << endl;
		for (auto it = results.begin(); it != results.end(); ++it) {
			cout << *it << endl;
		}
		cout << endl;

		sort(results.begin(), results.end(), lower_efficiency);

		const size_t n = min<size_t>(20, results.size());
		cout << n << " worst results:" << endl;
		for (size_t i = 0; i < n; i++) {
			cout << results[i] << endl;
		}
		cout << endl;

		cout << "cubic results:" << endl;
		for (auto it = cubic_results.begin(); it != cubic_results.end(); ++it) {
			cout << *it << endl;
		}
		cout << endl;

		sort(cubic_results.begin(), cubic_results.end(), lower_efficiency);

		cout.precision(2);
		vector<float> a = { 0.5f, 0.20f, 0.10f, 0.05f, 0.02f, 0.01f };
		for (auto it = a.begin(); it != a.end(); ++it) {
			size_t n = min(results.size() - 1, size_t(*it * results.size()));
			cout << (100.0f * n / (results.size() - 1))
				 << " % of product sizes have default efficiency <= " << 100.0f * results[n].default_efficiency << " %"
				 << endl;
		}
		cout.precision(default_precision);
	}
};

void
show_usage_and_exit(int argc, char* argv[], const vector<unique_ptr<action_t>>& available_actions)
{
	cerr << "usage: " << argv[0] << " <action> [options...] <input files...>" << endl;
	cerr << "available actions:" << endl;
	for (auto it = available_actions.begin(); it != available_actions.end(); ++it) {
		cerr << "  " << (*it)->invokation_name() << endl;
	}
	cerr << "the input files should each contain an output of benchmark-blocking-sizes" << endl;
	exit(1);
}

int
main(int argc, char* argv[])
{
	cout.precision(default_precision);
	cerr.precision(default_precision);

	vector<unique_ptr<action_t>> available_actions;
	available_actions.emplace_back(new partition_action_t);
	available_actions.emplace_back(new evaluate_defaults_action_t);

	vector<string> input_filenames;

	action_t* action = nullptr;

	if (argc < 2) {
		show_usage_and_exit(argc, argv, available_actions);
	}
	for (int i = 1; i < argc; i++) {
		bool arg_handled = false;
		// Step 1. Try to match action invocation names.
		for (auto it = available_actions.begin(); it != available_actions.end(); ++it) {
			if (!strcmp(argv[i], (*it)->invokation_name())) {
				if (!action) {
					action = it->get();
					arg_handled = true;
					break;
				} else {
					cerr << "can't specify more than one action!" << endl;
					show_usage_and_exit(argc, argv, available_actions);
				}
			}
		}
		if (arg_handled) {
			continue;
		}
		// Step 2. Try to match option names.
		if (argv[i][0] == '-') {
			if (!strcmp(argv[i], "--only-cubic-sizes")) {
				only_cubic_sizes = true;
				arg_handled = true;
			}
			if (!strcmp(argv[i], "--dump-tables")) {
				dump_tables = true;
				arg_handled = true;
			}
			if (!arg_handled) {
				cerr << "Unrecognized option: " << argv[i] << endl;
				show_usage_and_exit(argc, argv, available_actions);
			}
		}
		if (arg_handled) {
			continue;
		}
		// Step 3. Default to interpreting args as input filenames.
		input_filenames.emplace_back(argv[i]);
	}

	if (dump_tables && only_cubic_sizes) {
		cerr << "Incompatible options: --only-cubic-sizes and --dump-tables." << endl;
		show_usage_and_exit(argc, argv, available_actions);
	}

	if (!action) {
		show_usage_and_exit(argc, argv, available_actions);
	}

	action->run(input_filenames);
}
